THE MAASTRICHTIAN-DANIAN AT GENERAL ROCA: A REAPPRAISAL OF THE CHRONOSTRATIGRAPHY AND BIOSTRATIGRAPHY OF A KEY LOCALITY (PATAGONIA, ARGENTINA)

DEL RIO, CLAUDIA JULIA; CONCHEYRO, ANDREA; MARTINEZ, SERGIO

Neues Jahrbusch für Geologie Paläontologie

E. Schweizerbart’sche Verlagsbuchhandlung

Lugar: Stuttgart; Año: 2009 vol. 251

Abstract- The Late Cretaceous - Early Paleogene succession exposed in the type area of the Roca Formation (General Roca, Río Negro Province), has been sampled in detail. Analyses of the calcareous nannofossil assemblages indicates the Late Maastrichtian –Lower Danian interval (CC26-NP4 Zones; MARTINI 1971), being this, the first proved existence of the Late Maastrichtian in the mentioned type area. Moreover, the “Rocanense” invertebrate fauna has been placed in a high resolution biostratigraphic scheme based on the nannofossil zones, and three assemblages have been recognized.